Earth-moving machines, such as motor graders, are typically used for sculpting a surface of a construction site or roadway to a final shape and contour. Motor graders may be articulated, including a front frame and a rear frame connected together at an articulation joint. For example, the front frame may support a blade for grading the surface of the construction site or roadway, and the rear frame may support an operator cab and an engine. The engine may be operatively coupled to a set of rear tires for primary propulsion of the machine. The set of rear tires may include two pairs of tires with two axles in tandem, while the front frame may include one pair of tires on a front axle.
Generally, steering of the machine is a function of both front tire steering and articulation of the front frame relative to the rear frame. Due to the numerous controls currently needed for steering, controlling articulation, and positioning the blade, operators may experience difficulty and fatigue during operation. As a result, there is a need for sophisticated articulation control systems and methods that help minimize operator input for articulation control, thereby enabling convenient overall operation of the machine.
For example, U.S. Pat. No. 8,548,680, entitled, “Steering System with Automated Articulation Control,” describes a system and method of improving steering control for an articulated machine having front wheel steering. The system of the '680 patent receives steering commands from the operator. Based upon the steering commands or signals indicative of front wheel steering angle, the system of the '680 patent automatically commands articulation so that the rear frame will always be tracking the front frame of the machine. Thus, a controller of the '680 patent automatically controls an articulation angle based on a steering angle.
It should be appreciated that the solution of any particular problem is not a limitation on the scope of this disclosure or of the attached claims except to the extent expressly noted. Additionally, this background section discusses observations made by the inventors; the inclusion of any observation in this section is not an indication that the observation represents known prior art except that the contents of the indicated patent represent a publication. With respect to the identified patent, the foregoing summary thereof is not intended to alter or supplement the prior art document itself; any discrepancy or difference should be resolved by reference to the document itself.